Tony,
The Backing Sequencer mode on a Korg i30 is not a midi file. It a special file that not only allows the things your technics does but also allows change variations, fills having the intro play in the middle of a song and even clicking on the Ensemble mode which is the harmony voices for the right hand program etc.

I may be wrong, but I don't think midi files allows all of these things to happen do they while performing?